Rock drill



E. G. GARTIN June 12, 1934.

ROCK DRILL Filed oci. so, 1929 Patented June 12', 1934 UNITED STATES ROCK DRILL Elmer G. Gartin, Claremont, N. H., assgnor to Sullivan Machinery Company, a corporation of Massachusetts Application October 30, 1929, Serial No. 403,536

6 Claims.

This invention relates to rock drills and more particularly to improved drill steel rotation mechanism for rock drills of the hammer type.

An object of this invention is to provide an improved rock drill rotation mechanism. A further object is to provide an improved drill steel rotation mechanism for a rock drill of the hammer type having embodied therein improved release means for such rotation mechanism. An-

other object is to provide in a rock drill of the hammer piston type improved drill steel rotation mechanism of the intermittent ratchet and pawl type operated by the hammer piston of the drill `and having embodied therein improved release means for the rotation mechanism whereby when desired rotation of the drill steel may be discontinued while the hammer piston continues to operate. Still another object is to provide an improved frictional control for a rock drill rotation mechanism. These and other objects and advantages of this invention will, however, hereinafter more fully appear.

In the accompanying drawing there is shown for purposes of illustration three forms which the invention may assume in practice.

In this drawing- Fig. l is a central, longitudinally extending, sectional view through a rock drill having the preferred form of the improved rotation mechanism incorporated therewith.

Fig. 2 is a longitudinal vertical sectional view taken substantially on line 2-2 of Fig. 1 with -parts shown in elevation.

Fig. 3 is a transverse sectional view taken subfstantially on line 3-3 of Fig. 1.

Fig. 4 is a View similar to Fig. 2 illustrating a slightly modified form of the rotation release means.

Fig. 5 is a transverse sectional view taken substantially on line 5 5 of Fig. 4.

Fig. 6 is a view similar to Fig. 2 showing a further modified form of rotation release means.

In the preferred embodiment of the invention shown in Figs. 1 to 3 the improved rotation rel'ase means is embodied in a rock drill of the pressure fluid operated hammer type comprising a motor cylinder 1 having a bore 2 in which there is mounted for reciprocatory movement a hammer piston 3. The hammer piston is provided with a forwardly projecting striking bar 4 extending through a bore 5 formed in a front buffer ring or head block 6. This piston striking bar has formed on the exterior periphery thereof straight longitudinal grooves or il'utes '1 and cooperating with these grooves are straight keys or lugs 8 formed on a chuck nut 9 herein thread--V edly connected at 10to a rotatable chuck sleeve 11. As illustrated, connected to the chuck sleeve 11 as by clutch teeth 12 is a driver member 13 having usual lugs which are engageable with lugs formed on a drill steel 14. The shank of this drill steel is supported in a usual manner for reciprocatory movement within a chuck bushing 15 suitably secured to the rotatable chuck sleeve 11, and the shank of this steel projects into a position to receive a series of blows imparted thereto by the striking bar of the ham-i mer piston. As is usual in rock drills of the type disclosed, the chuck elements 11 and 13 are rotatably mounted within a chuck housing 16 having a rearward flanged portion 1'7 abutting against the forward surface of the `'front buiier ring 6. In the present construction the motor cylinder is provided with a combined rear head block and valve chest 18 having arranged therein a usual iluld distributing valve 19 which controls, in a well known manner, the fluid supply and exhaust of the motor. Abutting against the rear surface of the valve chest 18 is a sup'- plemental head member 20 having formed therein an enlarged bore 21 and a reduced bore 22. Arranged within the bore 21 is an intermittent ratchet and pawl type rotation mechanism 23 which includes an oscillatory pawl carrier 24 having formed integral therewith a rifle bar 25 85 extending forwardly through the bore 22 in the head 20 and the valve chamber and head block into the rear end of the hammer piston as clear--v 1y shown in Fig. 1. This rifle bar has formed on the exterior periphery thereof spiralgroovec 90 or utes 26 with which cooperate'spiral lugs or keys 27 formed on a rifle nut 28 suitably secured within the hammer piston. As clearly `shown in Fig. 3, the pawl carrier 24 has mounted thereon a plurality of spring pressed pawls 29 held in engagement with ratchet teeth 30 formed ina ternally within a ratchet ring 31 disposed within the bore 21 formed within the head 20. In this instance a circular plate 32 frictionally engages the annular rear face of the ratchet ring 31, holding the latter against rotation, and this plate is held in position by a rear head member 33 having a flange 34 abutting thereagainst. The rear head member 33,- plate the ratchet ring 31', the head blocks 20 ald`18, the mtoi cylinder' 1, the front buffer ring 6 and the chuck housing le are yieldably maintained in assembled relation by means of spring tensioned means, herein parallel side rods 35 passing through apertures formed inlaterally projecting lugs formed on the end members 33 and 16, and these rods are maintained under tension by means of coiled springs 36. From the foregoing description it will be evident that as the hammer piston 3 reciprocates within the motor cylinder, rotary movement is imparted thereto by the rifle bar and ratchet and pawl mechanism and this rotary movement of the piston is transmitted through the grooves on the striking bar, the chuck nut, chuck sleeve and driver member to the drill steel 14, a partial rotation being'imparted to the drill steel upon each rearward stroke of the hammer piston. As the structure and operation of the rock drill described herein is well known and does not per se enter into this invention other than in the manner in which it cooperates therewith, further detailed description of the same is thought unnecessary.

In rock drills of the type disclosed, particularly those especially adapted to use in quarry work wherein a broaching steel is sometimes used in place of the usual drill steel, it is desirable at times that the rotation of the steel be discontinued while the hammer piston continues to act on the steel. In the present construction the usual drill steel rotation mechanism has embodied therein the improved friction release means whereby the rotation mechanism may be rendered inoperative at will. This improved release means for the rotation mechanism includes an annular member or ring 37 rotatably mounted on the outer periphery of the rear head member 33 and having its forward surface abutting against the rear end of the head block 20 as shown in Fig. 2. As shown in Fig. 1, the annular member 37 has formed thereon inclined surfaces or cams 38 which engage correspondingly shaped inclined cam surfaces 39 formed on the head member 33. Projecting laterally from the annularmember 37 is an operating member or lug 40. .When the parts are in the position shown in Figs. 1 and 2 the ratchet ring 31 is frictionally held against rotation relative to the head block 20 by means of the circular plate 32 frictionally engaging the same. This plate 32 is maintained in frictional engagement with the ratchet ring by means of the head member 33 maintained in position by the spring tensioned side rods 35. When the parts are in the position shown, the rotation mechanism operates in anormal manner to effect intermittent rotation of the drill steel. When it is desired to render the rotation mechanism inoperative for anyfreason, for instance, if it is desired to use a broaching steel instead of the usual drill steel, the operator hammers against the operating lug 40 on the annular member 37, rotating the latter relative to the rear head member 33, thereby causing the cams 38 thereon to act against the cam surfaces 39 and the head member 33, thereby moving the latter slightly rearwardly against the tension of the side rod springs, relieving the pressure on the plate 32, thereby permitting the ratchet ring 31 to freely rotate within the bore 21 in the head block 20. -It will thus be evident that when the parts are in their released position and the ratchet ring 31 is permitted to freely rotate, the rifle bar 25 merely oscillates back and forth as the hammer piston reciprocates within themotor cylinder, the piston moving freely back and forth in a straight path without any rotation. When it is' again desired to impart rotation to the drill steel, the release member 37 is rotated into'the position shown in Fig. 1, thereby permitting the rear head member 33 to move in- Wardlyunder the tension of the side rod springs,

again frictionally locking the ratchet ring against rotation relative to the head block 20.

In the form of the invention shown in Figs. 4 and 5 the rotation mechanism and the improved release means therefor are substantially the same as those described above with the eX- ception that improved mechanism is employed for effecting rotation of the release member 37. This improved release mechanism includes worm gearv teeth 43 formed on the external periphery of the member 37. As shown in Fig. 5, secured to a transverse shaft 44 rotatably mounted Within a lateral housing 45 held in position by the rear head member 33 is a `worm 46 meshing with the Worm teeth 43. Secured to the shaft 44 is a hand wheel 47 whereby the worm gearing may be manually turned. With the release means disclosed in this form of the invention, When '.t is desired to interrupt the operation of the rotation mechanism, this is accomplished simply by turning the worm 46, thereby causing the release ring 37 to rotate relative to the head member 33. As a result of this rotative movement the cams 38 on the member 37 act against the cam surfaces 39 on the head, moving the latter against the tension of the side rod springs into its -released position, thereby permitting the ratchet Vring 31 to freely rotate. Otherwise this form of the invention is the same as that described above and therefore further description of the structure and operation of the same is thought unnecessary. Obviously the housing 45 is held against rotation.

In the form of the invention shown in Fig. 6 the rotatable release ring V37 and the cams and cam surfaces on the ring and the rear head member have beenY omitted. In this form of the invention a circular plate 48 is arranged within the bore 21 in the head block 20 in position to engage the rear surface of the ratchet ring 31. In this instance a set screw 49 is threadedly connected at 50 to the rear head member 33 and this set screw abuts against the plate 48. When this set screw is tightened, the plate 48 is held in frictional engagement with the ratchet ring, thereby holding the latter against rotation relative to the head block 20; As a result, the rotation mechanism operates `in a normal manner and the drill steel is rotated as the' hammer piston reciprocates. When it is desired to interrupt operation of the rotation mechanism, the set screwk 49 isloosened, thereby relieving the frictional engagement between the plate 48 Vand the ratchet ring 31, permitting the latter to freely rotate. Otherwise this form kof the invention is the same as that described above and therefore further detailed description of the same is thought unnecessary. If it be desired the plate 48 may be held against rotation by a spline or similar connection with the wallof the bore 21, or in any other manner, to reduce the dependence on friction between the screw 49 and plate 48.

As a result of this invention, it will be noted that an improved drill steel rotation mechanism is provided for a rock drill of the hammer piston type having embodied therein improved release means whereby the rotation mechanism may be rendered inoperative at will while the hammer piston continues to operate in a normal manner. It will further be noted that an improved frictional release means is provided for a drill steel rotation mechanism which may be applied to a rock drill of a standard design with a minimum of change, the friction release means including many of the standard drill parts. It will still further be evident that an improved friction release means for a drill steel rotation mechanism is provided which acts directly on the side rod springs, the latter being normally adapted to maintain the rotation mechanism operative and having means associated therewith for relieving the tension of the side rod springs on the rotation mechanism, thereby rendering the latter inoperative. These and other uses and advantages of the invention Will be clearly apparent to those skilled in the art.

While there are in this application specifically described several forms which this invention may assume in practice, it will be understood that these forms of the same are shown for purposes of illustration and that the invention may be modied and embodied in various other forms Without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

l. In a rock drill, a cylinder, front and rear heads therefor, means under tension for holding said cylinder heads in assembled relation, yieldable tensioning means for said holding means, a hammer piston reciprocable in said cylinder, a drill steel actuated by said piston, drill steel rotation mechanism including a ratchet and pawl mechanism operated by said piston including a rotatable ratchet ring normally held against rotation by said holding means, and rotation release means operable at will to act on said yieldable holding means to release completely said ratchet ring from the holding action of said holding means thereon for permitting, while said cylinder heads and cylinder remain in their assembled relation relative to each other, said ratchet ring to rotate freely to interrupt the operation of said rotation mechanism While said hammer piston continues to operate, said tensioned means exerting at least as great a holding force on the motor parts when the ratchet ring element is released as when the latter is held against rotation.

2. In a. rock drill, a cylinder, front and rear heads therefor, a spring tensioned element for holding said cylinder and heads in assembled relation, a hammer piston reciprocable in said cylinder, a drill steel actuated by said piston, drill steel rotation mechanism operated by said piston including a rotatable rotation element, means held in position by said tensioned element for holding said rotation element against rotation to permit said rotation mechanism to normally operate, and means including manually controllable means operable at Will for increasing the tension of said tensioned element to release the holding action of said holding means on said rotation element to permit said rotation element to rotate freely to interrupt operation of said rotation mechanism.

3. In a rock drill, a drilling motor including a plurality of parts, means under tension for holding the motor parts in assembled relation, said motor parts including a cylinder, and a hammer piston reciprocable in said cylinder, a drill steel actuated by said piston, drill steel rotation mechanism including a rotatable rotation element normally held against rotation by said holding means, and means operable at will to act on said holding means for releasing completely said element from the holding action of said holding means thereon and While the motor parts are maintained in their normally assembled relation to permit free rotation of said rotation element, thereby interrupting operation of said rotation mechanism, said tensioned means exerting at least as great a holding force on the motor parts when the rotation element is released as when the latter is held against rotation.

4. In a rock drill, a drilling motor including a plurality of parts, means un-der tension for holding said motor parts in assembled relation, said motor parts including a cylinder, and a hammer piston reciprocable in said cylinder, a drill steel actuated by said piston, drill steel rotation mechanism operated by said piston including a rotatable rotation element normally held against rotation by said holding means, and means arranged entirely between the ends of said holding means and operable at will to act on said holding means for releasing completely said element from the holding action thereof to permit free rotation of said rotation element, thereby interrupting rotation of said rotation mechanism, said tensioned means exerting at least as great a holding force on the motor parts when the rotation element is released as when the latter is held against rotation.

5. In a rock drill, a drilling motor having a plurality of parts, spring tensioned means for holding said motor parts in assembled relation, said motor parts including a cylinder, and a hammer piston reciprocable in said cylinder, a drill steel actuated by said piston, drill steel rotation means including a rotatable rotation element normally frictionally held against rotation by said spring tensioned holding means, said spring tensioned means being yieldable to permit rotation of said rotation element to vary the operation of said rotation means, and means operable at will to act on said spring tensioned means for releasing said rotation element from the holding action of said holding means thereon to interrupt operation of said rotation means, said spring tensioned means exerting at least as great a holding force on said motor parts when said rotation element is released as when the latter is held against rotation.

6. In a rock Idrill, a drilling motor having a plurality of parts and means for resiliently holding said parts in assembled relation, said drill comprising automatic rotation mechanism including a reaction element normally held against rotation by the tension of said holding means, and means operable to act against the force of said resilient holding means to release said reaction element at Will from the holding action of said holding means thereon.

ELMER G. GARTIN. 

